Cage Project Sponsored by OAHF Aids Sea Lions on Oregon Coast

A team of scientists, veterinarians and volunteers have deployed a custom-built “capture cage” in Newport to temporarily sequester sea lions that have become entangled with rope, fishing line and other materials so they can be untangled.

The cage is located on the bayfront at Dock 1, where coastal visitors frequently see the animals sunning themselves on the floating dock.

The Oregon Animal Health Foundation, the charitable arm of the Oregon Veterinary Medical Association, provided a $5,000 grant for the project.

Jim Rice of Oregon State University, who coordinates the multi-agency Marine Mammal Stranding Network, said removing debris from the animals can be difficult and dangerous.

“Because entangled animals are generally active and defensive, options for removing debris are very limited,” said Rice, who is affiliated with OSU’s Marine Mammal Institute. “Sea lions will not tolerate close approach and unrestrained anesthesia is deemed too dangerous for the animals since a sea lion injected with drugs by a pole or dart would likely flee to the water only to subsequently drown.”

However, doing nothing may also doom the animals, Rice pointed out. Steller sea lions on the West Coast are listed as “threatened” under the Endangered Species Act and the waste debris from human activities increasingly is posing a risk to these animals and other marine species.

“When you visit the Newport bayfront, it isn’t unusual to observe California sea lions with various forms of entanglement – especially plastic “packing bands” wrapped tightly around the neck, cutting into the animal’s skin, blubber and muscle,” Rice said. “But despite these animals’ proximity to a public viewing pier, they are not nearly as accessible to would-be rescuers as they may appear.”

Thus Rice and colleagues will use a cage built by Mulder Sheet Metal, Inc., in Newport that was based on designs from the Oregon Department of Fish and Wildlife. The cage is basically a modified floating dock enclosed on four sides by a galvanized steel structure, with sliding doors on two sides. It is designed primarily to serve as an additional “haul out” area for sea lions to use freely, with its doors locked in the open position so animals can comfortably come and go as they choose.
“Once they become comfortable with using the dock, we can close the cage doors when we spot an entangled animal and then address the entanglement,” Rice said.

Entangled sea lions will be anesthetized and then treated by veterinarians. Veterinary medical services will be provided by Dr. Steven Brown and Dr. Daniel Lewer of Animal Medical Care in Newport, with logistical support from the Oregon Coast Aquarium.

Kim Raum-Suryan, a marine mammal specialist with OSU’s Hatfield Marine Science Center, says entanglement of marine mammals is a global problem.

“In our studies in southeast Alaska, we estimated that as many as 60 individuals were visibly entangled at any given time and there were likely many more that were not observed,” Raum-Suryan said. “Most of the entanglements were from thick plastic packing bands used to wrap bait boxes, but fishing line, nets, large rubber bands and other materials can be equally dangerous.
“Thousands of marine animals are estimated to die each year as a result of entanglement, or ingestion of marine debris,” she added. “We’ve had the same issues with animals at Sea Lion Caves and off Cascade Head. I spotted four juvenile Stellers in one day that were entangled.”

Advocates are working with bait manufacturers and others on different, less dangerous wrapping materials. But common sense also can be applied, Raum-Suryan said.

“First, don’t litter,” she pointed out. “And if you find trash on the beach, consider picking it up and discarding it. But it’s also a good idea to cut any banding in half in case it mistakenly gets into the water.”

The entanglement relief project involves several partners, including Animal Medical Care, the Port of Newport, Oregon Marine Mammal Stranding Network, Oregon State University Marine Mammal Institute, Oregon Coast Aquarium, and the Oregon Department of Fish and Wildlife.

Other funding and partnership includes the Oregon Coast Aquarium, the Marine Mammal Institute, OSU, and NOAA’s John H. Prescott Marine Mammal Rescue Assistance Grant Program, which provides support for the Oregon Marine Mammal Stranding Network through OSU’s Marine Mammal Institute.